resistor power rating

A wattmeter dial with glowing wires linking a voltmeter, an ammeter and a lamp, beside the title How Electronics Work, Part 8, How Electrical Power Works
How Electrical Power Works: Mastering Fundamental Electronics Part 08
DIY Electronics
Learn how electrical power works: watts as a rate, P = VI, resistor heating, source and load signs, efficiency, and a worked LED resistor example.